Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
luat tuc » luat thue
chat tuc » chat xuc, chat huu, chat cua
su sach » so sach, vu sach
va hanh » van hanh, va thanh, va danh
hieu va » lieu va, hieu qua
nang xa » nang x, lang xa, nang ma
cua tre » cua te, cuu tre, cua triet
vi cua » vai cua, di cua

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: ((su sach) or (thuoc sach)) ky nang xa hoi. hieu va ((chat tuc) OR (luat tuc)) va hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (thuoc sach)) ky nang xa hoi. hieu va ((chat tuc) OR (luat tuc)) va hanh vi cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) or (thuoc sach)) ky nang xa hoi. hieu va ((chat tuc) OR (luat tuc)) va hanh vi cua tre*".